The adulteration of gloves used in surgery has long been a problem to the medical doctor. Glove adulteration as used herein is intended to encompass glove conditions such as holes formed during manufacture as well as holes formed thereafter for any reason. The term "holes" includes incipient holes, which may be too small to pass water but may enlarge over time, or otherwise breach or deteriorate the integrity of the glove wall. There are two sources for the creation of holes or perforations in surgical gloves. One source is the manufacturer who, due to lack of quality control or inherent manufacturing problems, may manufacture and sell gloves which already have perforations. Recently, the Federal Food and Drug Administration has determined by field inspection failure rates of three to sixteen percent in surgical gloves. The FDA further found that, for patient-examination gloves, average defect rates range from fourteen to eighteen percent. In a recent attempt to tighten the quality control in surgical gloves, the FDA has resorted to the well-known and fundamental technique for determining defects in gloves--a water fill test. The water fill test is only capable of detecting holes large enough to actually pass water. Danger exists when a hole is large enough to expose skin on the other side of the glove to harmful bacteria or virus even though the hole is not large enough to actually allow water to pass through the hole during the water fill test.
The second source of holes or perforations in gloves occurs during use. For example, holes or dangerously thin spots may develop in gloves at the time that the surgeon first fits the gloves over his or her hands, or, a glove may be perforated during surgery. Perforations during surgery can occur because of sharp objects or because of the breaking down of inherently thin spots in the gloves or areas made thin as a result of putting the glove on the hand. Perforations expose the surgeon to actual or possible adulteration of the surgical gloves with body fluids. While such adulteration has always been a possible source of infection or the spreading of bacteria to the surgeon, the alarming spread of the hepatitis and AIDS viruses has created an even more serious problem--the possible spread of an incurable disease to the surgeon. Therefore, the need for accurate and immediate detection of actual or near-adulteration in surgical gloves is now at a heightened level because of the potential for the spread of incurable diseases from patient to surgeon or vice-versa.
The problems with the AIDS virus is not limited, however, to surgeons. For example, it is possible that other users of critical use gloves such as dentists may be subject to many of the same serious concerns because the dentist is also exposed to body fluids during his or her work on a patient. While perhaps less likely, there is also some possibility for the spread of serious diseases from patients to doctors during physical examinations. For purposes of definition, doctors, dentists, nurses and others who may be exposed to disease through gloves or other barriers are defined herein as "health are workers."
While the FDA has taken the approach of using a tried and true method of simple water fill to determine leaks in gloves as manufactured, it is obvious that such simple techniques cannot be used to detect actual or near-adulteration in gloves during use. There have been some attempts in the prior art to detect the occurrence of perforations in surgeons gloves after the gloves are on the doctor's hands. U.S. Pat. No. 4,321,925 of John Hoborn and Ulrich Krebs discloses an electronic detector arranged so that the level of electronic conductivity through the gloves and between the patient and the surgeon may be sensed at regularly recurring discrete time intervals in order to measure a predetermined level of sensed conductivity and signal an alarm if such predetermined level is met.
The detecting circuit of the '925 patent is actually located in one of the shoes of the surgeon and includes one contact located in the insole of the shoe in order to make electrical contact with the surgeon and a second contact exposed to an electrically conducting plate located on the floor of the operating room so that a closed circuit is formed between the operating table, the patient, the doctor, the electronic device located in the shoe and the round conducting element or plate located on the floor of the operating room. The '925 patent teaches that five times per second the disclosed circuit short-circuits the contacts in the insole and in the bottom of the sole of the shoe in order to discharge static electricity from the insole contact which may have accumulated from the doctor. After each short circuit, the circuit is opened between the two contacts and a voltage level sensor is used to detect the electrical conductivity which occurs externally between the contacts.
The impedance of the rubber or latex which comprises the surgical gloves is high. If there is a perforation in the operating gloves of the surgeon, the impedance is thereby reduced and a greater conductivity is provided through the gloves. The '925 patent teaches that the occurrence of a perforation in the operating gloves may allow a relatively high electric conductivity between the surgeon and patient thus allowing the sensing device to sound an alarm upon the occurrence of a predetermined level of sensed conductivity.
Setting of the appropriate level of conductivity is strictly a matter of design and thus it is believed that one drawback to the device of the '925 patent is that the level of conductivity required to trigger the alarm may differ from glove to glove, depending upon the nature of the material, the thickness of the material and any other factors which may impact upon the general conductivity of the series circuit, which includes not only the doctor and patient, but also the doctor's shoes, a round plate located on the operating floor, and the operating table itself. Therefore, the '925 patent may work fairly well for certain types of gloves whose characteristics conform to the particular voltage level chosen for the voltage level sensor, but the '925 patent may not work well with many other types of gloves. In order to function properly, the voltage sensor in the '925 patent may have to be adjusted depending on the type of gloves used. The fact that the absolute conductivity of a glove may vary with the amount of water absorbed in the glove material may also detract from the efficiency of the sensor of the '925 device.
Other prior art devices include several devices which have been disclosed in patents which utilize a basin of conductive fluid in which the surgeon places his or her gloved hands for the purposes of determining whether or not the glove may become adulterated due to immersion. If the conductive fluid in the basin enters a gloved hand, increased conductivity is detected. Other devices and relevant prior art are discussed in an Information Disclosure Statement.
It is submitted that there is need for the development of further, more sophisticated detection methods and apparatus in order to detect not only actual adulteration but near-adulteration of surgical or other critical use gloves. This detection method should also preferably not interfere with the normal activities of the user. The terms "near" or "likely" adulteration of the glove are intended to mean that a hole has just formed or a thin spot had suddenly developed which greatly increases the chances of actual adulteration. In addition, there is a need for detection methods which do not necessarily depend on the absolute level of conductivity of particular operation gloves but are capable of detecting changes in glove condition.